Cut tobacco stemmer



United States Patent lvano Pietralunga Bologna, Italy Feb. 23, 1968 Nov. 24, 1970 American Machine 81 Foundry Company a corporation of New Jersey [72] Inventor [21] Appl. No. [22] Filed [45] Patented [73] Assignee [54] CUT TOBACCO STEMMER 13 Claims, 4 Drawing Figs.

[52] US. Cl. 131/109, 131/1 10: 209/133, 209/137 [51] Int. Cl. ..A24c 05/39, B07b 04/02, B07b 13/10 [50] Field ofSearch 131/1098, 110, 110A, 110AA, 146; 209/133T, 136, 137(Lutter) [56] References Cited UNITED STATES PATENTS 518,082 4/1894 Stuckey etal. 131/110UX 1,903,931 4/1933 Molins et a1. 131/110 2,130,880 9/1938 Durning ..209/133(T)UX 3,074,413 1/1963 McArthurQ. 131/110x 3,092,117 6/1963 Labbe 131/110 3,189,034 6/1965 MOllnS 131/110x 3,262,457 7/1966 Gamberini..... 209/137x 3,362,414 1/1968 Wochnowski 131/146 FOREIGN PATENTS 746,106 3/1956 (11690131116111 131/110(AA) 1,015,194 12/1965 GreatBritain. 131/110(AA) 645,794 9/1962 ltaly 131/110(AA) Primary Examiner Samuel Koren Assistant Examiner-James H. Czerwonky Atto rneys-George W. Price and Eli Weiss ABSTRACT: An apparatus and method for separating out tobacco components into fractions, which comprises a baffle means and means for ballistically projecting said cut tobacco. The cut tobacco is ballistically projected toward the baffle means and at least a first group of heavy fractions are trapped by the baffle means and are removed therefrom. Pneumatic blow means pneumatically propel the remaining cut tobacco to remove additional fractions from the remaining cut tobacco and leave a residue of cut tobacco for separately collecting each of said fractions and the residue of said cut tobacco.

' Pitmdt 24,1970 3,542,037

I I Sheet 014 INVENTOR IVANO PIETRALUNGA BY M T ORNEY Pater ited; 1970 Sheet INVENTOR ATTORNEY IVANO PIETRALUNGA Patent ed :Nov. 24, 1970 Sheet 1 Patented Nov. 24, 1970 Sheet 1: of 4 [Pit -L FE l.||||.ll|| 'Ill INV ENT OR IVANO PIETRALUNGA Gav ATTORNEY This invention relates to the so-called stemming apparatus or stemmers of cut tobacco,thatis'to say, ausually independe'ntor self-containing apparatus for separating the components of cut or shredded tobacco into various fractions containing particles of similar size or weight, said components including the shredded tobacco proper on. one hand and the various impurities to begin with the stems of the tobacco leaves and other heavy impurities including foreign matters such as, for ,example, pieces of tissue or-c'ords, nails, metal fragments, sand or very small stones and the like.

The object of the invention is to provide an apparatus for separating said'cut tobacco components into at least three fractions and comprises means for ballistically projecting said cut tobacco, whereby at least some of said fractions are removed therefrom, means for pneumatically propelling said remaining cut tobacco, whereby additional fractions are removed and means for separately collecting each of said fractions of separate particles and the residue of said cut tobacco.

Thus the invention aims to provide a so-called tobacco stemmer in which theshredded tobacco separated fromits impurities includes practically the whole of the shredded tobacco leaves, duly stemmed'and, deprived of all impurities, while the separated impurities do notpractically contain any parts of shredded tobacco leaves proper, thus reducing at the minimum the amountof valuable fraction of tobacco leaves rejected or otherwise wasted.

The stemmerand 'cut tobacco component separator according to the invention comprises preferably a first unit for districating or disentangling the mass of shredded tobacco to be deprived of its impurities, then a unit for separating the fraction including the heaviest impurities (such as large stems and foreign matter) by ballistic throwing and then for eliminating nonliniiting example in the accompanying drawings, in which:

FIG. I shows in perspective a cut tobacco fractions separating apparatus or stemmer" according 'to the'invention;

' FIG; 2 is a longitudinal vertical section of the same; FIG. 3 is a diagrammatic view in front elevation of the lower part of the stemmingapparatus alongthe line 3-3 of FIG. 2

' comprising the unit for separation by ventilation;

FIG. 4 shows diagrammaticallyin plan view the arrangement of a plurality of tobacco stemmers according to the invention. n v

a With referenceto the FIGS., the stemmer according to the invention joins'in a single independent unit a group A for mechanically feeding and disentangling the mass of shredded unthrashed and unstemmed shredded; a group B for the ballistic separation, that is, by projecting the stems and the other heavy impurities of the shredded tobacco and a subsequent groupC for the pneumatic separation, that isby means of ventilation, of the stems and of the other impurities remained within the shredded'tabacco after the ballistic selection.

With a particular reference to FIG. 2, the feeding and disentangling unit A' comprises a hopper 1, into which the unstemmed shredded tobacco is charged. The bottom of the hopper l is constituted by a belt 2 which travels in the direction of the arrows'and carries the shredded tobacco towards a device similar to the devices being employed for carding the shredded tobacco in the feed hoppers of the cigarette-making machines and is preferably constructed according to other patents of the same patent'ee to which (patents) it is to be referred to for more details. Such a device substantially comprises a carding pin drum 3, revolving in the direction of the'arrow, and which, by means of the revolving raked, picks up from the shredded tobacco charged in the hopper 1, a thin veil of tobacco; This tobacco veil is levelled on the carding drum 3 by means of an overlying equalizing cylinder 5. On the descending side of the drum 3, opposite to the hopper l, the veil of carded tobacco. is discarded from the carding drum 3 by'means of the discarding pin drum :6, and is fed to the throwing revolving drum 7, which throws (or hurls) the shredded tobacco into the unit B for the ballistic separation.

The unit B for the ballistic separation comprises a conveyor belt 8-.traveling in'the direction of the arrow and inclined with 'respect to the carding unit 3-5 is driven in an upward direction. At a certain height above the said belt 8 and above the throwing drum7 there are transversal collecting channels or gutters which are made lengthwise, or at least in correspondence of their hollow part, a convex shape with the highest point or summit in correspondence of their midline. Between the channels 109 and the channel 209 there are chutes 10 arranged, inclined towards the same channel 209. The channels 9, 109, 209 and the chutes 10 are caused to vibrate by means of any conventional suitable means B, such as an electromagnet' and armature arrangement designed to operate as a buzzer, or an electric motor having an unbalanced weight attached to its armature or the like (not illustrated). The vibrations move the particles along the channels and the chutes from the center toward the sides downhill. Preferably the channels 9 and 209 are part of a vibrating system, while the channels 109 and the chutes 10 are part of another vibrating system. Thus, the channels 9 and 209 are coupled to one vibrating system such as a buzzer or a motor; and, the channels 109 and chutes 10 are coupled to another vibrating system such as a buzzer or a motor. The chutes 10 do not have convex bottoms.

The openings of the channels and chutes and their position from the drum 7 is such that the filaments of the shredded tobacco blown by the projecting drum 7, being lighter, do not reach the channels 9, 109, 209 and therefore fall onto the belt 8, while the stems and the other heavier impurities are hurled within the area of the channels 9, 109, 209 and of the chutes l0 and therefore fall into'the said collecting channels 9, 109, 209. The stems and the impurities which fall onto the chutes 10 are fed by the same to the collecting channel 209. The convex shape of the channels 9, 109, 209, and the longitudinal vibration of these channels cooperate to urge the stems and the impurities collected to slide into each channel from the midline towards both of its ends.

Oneither side of themachine a collecting hopper 11 is provided which opens with its lower end 111 over a conveyor belt 12 mounted in the lower part of the stemming machine and designed to collect and unload the stems and the other impurities separated from the shredded tobacco. The upper collect- "ing channels 9, I09, 209, (FIGS. 1 and 2) with a convex or inverted V-shaped longitudinal profile, with both of their ends opening into the respective side hoppers 11. Therefore, the stems and the impurities'collected within the said channels 9, 109, 209. by the effect of the vibration of the channels, move down into the side hopper 11 and by the same are discharged onto the lower collecting belt 12.

' The stems and the impurities which are not separated by the aforementioned ballistic selection, for example entrained by the fibers of the shredded tobacco, fall together with the same onto the belt 8. The tobacco collected by the belt 8 is therefore conveyed to the unit C for selection through pneumatic blow means or ventilation, into which the stems and the impurities still contained within the shredded tobacco are separated from the latter by the action of air currents (pneumatic selection).

The unit C for the selection-by ventilation is arranged under the units A and B, that is, under the collecting belt 8 and comhanded one, and are connected by means of conduits 16 and 17 to a collecting main 18. Both conduits 16, 17, and the main 18 extend in a longitudinal direction of the machine. The collecting main 18 opens, from the stemming machine into the feeding head end of the same, below the hopper 1, and is connected to a piping (not shown) for the pneumatic conveyance by suction of the stemmed shredded tobacco.

Both ventilation chambers 13, 14 are interconnected by a short inclined conduit 19, and each of them presents an inclined perforated bottom portion 113, 114. At the lower end of the perforated bottom portion 113, 114, each ventilation chamber 13, 14-presents a bottom opening 213,214 which extends for the whole or almost the whole width of the machine and opens over the collecting drum 12. The inclined portions 113, 114 of the two ventilation chambers 13, 14 are connected together by means of the lower wall or bottom portion of the intercommunication conduit (19). The bottom portion 114 of the lower ventilation chamber 14 is coplanar with the bottom portion of the intercommunication conduit 19 and these two portions are slightly higher than the bottom portion 113 of the upper ventilation chamber 13. Consequently, the bottom opening 213 of the upper ventilation chamber 13 is defined, along its lower edge, by an edge 20 which is slightly higher than the opposite or upper edge of the said opening 213, as it is apparent in FIG. 2.

The perforated portions 113, 114 of both ventilation chambers 13, 14 form the top closure wall of two boxes'21 and 22 which are both comparted into two sections, the right one and the left one, similarly to the ventilation chambers 13, 14 proper, as it is made apparent by FIG. 3 for the box 22 of the lower ventilation chamber 14. On each side of the machine a fan 23, 24, is provided. The right-hand sections of both boxes 21, 22 are connected to the intake opening of the right-hand ventilator 23 by means of pipe 123. Similarly, the left-hand sections of both boxes 21, 22 are connected to the intake opening of the left-hand ventilator 24 by means of the pipe 124.

Under these conditions, the separation by ventilation of the stems and of the heavy impurities from the tobacco within the aforedescribed unit C for a pneumatic selection, is performed under the combined effect of the suction exerted through the collecting main 18 for discharging the stemmed shredded tobacco, and of the supplementary air blown by the fans 23, 24 into the two chambers 13, 14 through the respective perforated bottoms 113, l14. The shredded tobacco, already partly stemmed withinthe unit B for the ballistic selection, is caused to fall from the collecting belt 8 down into the first ventilation chamber 13, substantially tangentially with respect to the bottom 113 of the same. Within this chamber 13, a great part of the shredded tobacco is blown up by the air blown through the perforated bottom 113 and gets into the conduit 16, thus arriving into the collecting main 18 under suction. On the contrary, the stems and the impurities continue their downward travel within the chamber 13, keeping almost close to the bottom 113, so that they fall, at the end of said bottom, down through the opening 213 onto the lower collecting belt 12. The suction exerted through the collecting main 18 for the discharge of the shredded tobacco produces an air return through the rear grate 25 and an ascending air stream through the bottom opening 213 of the chamber l3. Tobacco shreds which could be entrained by the stems into the box 21 through the bottom opening 213 ofthe chamber 13 are blown up again by the said ascending stream through the opening 213 and again brought into the chamber 13, from which they may enter into the conduit 16.

The shredded tobacco, the stems and the impurities resulting from the first separation in the upper ventilation chamber 13, pass through the conduit 19, over the edge 20, into the lower ventilation chamber 14, in which they undergo the same separating action as when in the upper chamber 13. The remaining part of the shredded tobacco is thus blown up from the perforated bottom 114 of chamber 14, by the effect of the air blown through such a bottom 114 proper, and flows into the conduit 17 in order to get into the collecting delivery main 18, while the remaining stems and the other impurities fall onto the lower collecting belt 12 through the bottom opening 214, where the ascending air stream, induced by the suction through the grate 25, again blows up and sends back into the chamber 14 the shredded tobacco which could have been entrained by the fall of the same stems.

The lower collecting belt 12 delivers the stems onto a perforated belt 26 under which a vibrating collecting channel 27 or another conveyor, is arranged. The so-called partridge eyes or cross-sectional segments of the tobacco fall down through the perforations of the belt 26 into the underlying vibrating collecting channel 27 and are discharged and recovered through the side outlet 127 ofthe same.

in FIG. 4 is shown by way of an example, the diagram of a plant constructed by employing the stemming machines according to the invention. In this case, five stemming machines Ml-MS of the aforementioned type are employed. Four of these machines M1-M4 work in parallel and deliver the stemmed shredded tobacco into the tube T, for the pneumatic conveyance under suction, connected with the collecting mains 18 of the said machines. The stems mingled with partridges eyes and possibly with remainders of shredded tobacco are delivered by the machines Ml-M4 onto two confluent perforated belts 26. The partridge eyes, collected under these perforated belts 26 are recovered and conveyed by means of tubes D into the tube T for the pneumatic conveyance of the stemmed shredded tobacco, The stems and the remainders of shredded tobacco carried by the perforated belts 26 are collected in R, and sent to the fifth stemming machine M5, which separates from the stems the remaining shredded tobacco. Also this recovered shredded tobacco is conveyed, by means of the tube E, into the pneumatic conveyance tube T, while the stems are rejected through S.

Of course, the invention is not limited to the embodiment as just described and shown, but it can be widely varied and modified, above all in construction, without departing from the leading principle as above specified and claimed hereinafter.

Y lclaim:

1. Apparatus for separating the components of cut tobacco into various fractions, each fraction containing particles of similar size or weight, comprising a baffle means, for ballistically projecting said cut tobacco toward said baffle means, whereby at least a first group ofheavy fractions are trapped by said baffle means and are removed therefrom, pneumatic blow means coupled to pneumatically propel said remaining cut tobacco to remove additional fractions from said remaining cut tobacco and leave a residue of cut tobacco, and means for separately collecting each of said fractions of separated particles and the residue ofsaid cut tobacco.

2. A method of separating the components of cut tobacco into various fractions, each fraction containing particles of similar size and weight, comprising the steps of first ballistically projecting said cut tobacco to form a first group of heavy fractions and a second group of remaining cut tobacco, thereafter pneumatically propelling said second group of remaining cut tobacco to separate additional fractions from said second group of cut tobacco, and collecting each of said fractions and the remainder of said cut tobacco separately.

3. An apparatus for separating the components of cut tobacco comprising a carding pin drum for picking up shredded tobacco from a feed hopper and disentangling same, pin drums for discarding a portion of the tobacco from the said carding pin drum and means for hurling forwards the tobacco remaining on said carding drum so as to ballistically throw the heaviest particles along an upper trajectory and the remaining particles along a lower trajectory, a set of channels spaced along the upper trajectory and each provided with a bottom portion to receive said ballistically thrown heaviest particles, each of said bottom portions being convex transversely to said upper trajectory, hoppers arranged sidewise of said channels for receiving the heaviest particles from said channels and pneumatic blow means for furtherpropelling the remaining shredded tobacco, said chamber having an inclined perforated I bottom portion; meanslfor blowing air through said bottom portion; means for feedingthe shredded tobacco to be stemmed substantially tangent to the upper end of said inclined perforated bottom portion, an opening at the lower end of said bottom-portion for receiving and directing the stems to a stem-collecting belt.

7. Apparatus according to claim blow means comprises two ventilation chamberscommunicatingone with each'other,-arranged in a descending order, each coupled to a source ofsuction through a common collecting main for the delivery of the shredded tobaccof.

8. Apparatus according to claim 7 including a transversed' edge interposed between the bottom portions of the first and second ventilation chambers and which forms-the lower edge of the opening provided in the bottom of the first chamber and through'which the stemsfall onto said stern-collecting belt 9. Apparatus according to claim-3 in which the carding and feeding section and the section for the ballistic selectionare arranged above. the pneumaticblow. means; a stemmed shredded tobacco-collecting belt separating the section for the ballistic selection from the section for the pneumatic blow means, said belt feeding the shredded tobacco to said pneumatic blow means, and a belt for collecting stems arranged beneath thepneumatic blow means.

10. An apparatus according to claim 9, comprising further a perforated belt arranged on the dischar'ging'end of said stemcollecting belt, said perforatedbelt serving for collecting and recovering stem section segments contained inthe shredded tobacco and whichfall down through the perforations of the said perforated belt. I v

11. Apparatus forseparating the heaviest particles, such as stems and heavy foreign matterfrorn shredded tobacco, comprising a housing, a hopper at one top end of said housing for charging the shreddedtobacco to be deprivedof its heaviest 6, of which the pneumatic particles, a first belt conveyor forming the bottom of said hopper; a carding drum forming an end wall of said hopper, arranged at one end 'of said first belt conveyor; a pin drum for detaching said shredded tobacco from said carding drum and a rapidly revolving drum adjacent to said pin drum for hurling ballistically by centrifugal action said shredded tobacco removed from the carding drurn; a plurality of baffle'rneans, each inclined downwardly transversely of the trajectory of said heaviest particles and receiving the heaviest particles thrown farthest distant from said centrifugal drum; heaviest particle collecting means arranged at the lowest ends of said baffle means anddelivering said heaviest particles to a discharge means; a second endless conveyor arranged beneath said centrifugally hurling drum and receiving and conveying the remaining shredded tobacco particles; a tunnellike duct arranged beneath said second endless conveyor; means for suctionally conveying the lightest of said remaining particles towards an outlet end and deflecting means for directing the heaviest of said remaining particles onto said discharge means .12. Apparatus according to claim 1 1 in which the tunnellike duct has a, perforated bottom wall provided with a slit provided with a stepped edge forming said deflecting means and opening into a chute, and an outwardly open outlet mouth past said stepped edge; a fan blowing air through said perforated bottom wall so as to pneumatically propel the lightest tobacco particles towards said outlet mouth, while allowing the heaviest particles to about against said stepped edge and fall down said chute said discharge means comprising a third conveyor for collect ng all heavy particles separated rom the separating both the heaviest particles coming from the fresh shredded tobacco and those coming from the said parallel separators. 

